In the following common emitter circuit, if =100, V_ C E =-7 ~V , V_ B E is negligible, R_C=2 k , then I_B= ?

Step-by-step solution

aligned & Given that, V_ C E =-7 ~V , =100 & R_C=2 k =2000 , V_ C C =15 ~V aligned We know that, the current gain in common emitter circuit is =I_C / I_B...(i) By KVL in right loop, V_ C C -I_C R_C+V_ C E =0 Substituting the values, we get aligned 15-I_c(2000)-7 & =0 I_C & = 8 2000 =4 ~mA ...(ii) aligned Putting value of I_C in Eq. (i), we get aligned & =4 / I_B 100=4 / I_B & I_B= 4 100 ~mA =0.04 ~mA aligned